The pH of a saturated solution of a metal hydroxide of formula X(OH)₂ is 12.0 at 298 K. What is the solubility product of a metal hydroxide at 298 K (in mol³ L^-3)?

• 5 × 10^-7

• 2 × 10^-6

• 1 × 10^-7

• 5 × 10^-5

An inorganic salt (A) is decomposed on heating to give two products (B) and (C). Compound (C) is a liquid a room temperature and is neutral to litmus while the compound (B) is a colourless neutral gas. Compounds (A), (B) and (C) are 

• NH₄NO₃, N₂O, H₂O

• NH₄NO₂, NO, H₂O

• CaO, H₂O, CaCl₂

• Ba(NO₃)₂, H₂O, NO₂

The sum of pH and pK_b for a basic buffer solution is 13. The ratio of the concentration of the base to that of the salt is

• 10

• 1

• 0.05

• 0.1

Two equilibria, AB $\rightleftharpoons$ A +B. are simultaneously maintained in a solution with equilibrium constants, K₁ and K₂ respectively. The ratio of [A⁺] to [AB${}_2^{-}$] in the solution is

• directly proportional to [B^-]

• inversely proportional to [B^-]

• directly proportional to the square of [B^-]

• inversely proportional to the square of [B^-]

A current strength of 9.65 A is passed through excess fused AlCl₃ for 5 h. How many litres of chlorine will be liberated at STP? (F = 96500 C)

• 2.016

• 1.008

• 11.2

• 20.16

The colour of the soltuion/ precipitate obtained in the elemental analysis of an organic compound and the molecule/ion responsible for the colour are given below. Choose the incorrectly matched pair.

• Prussian blue - Fe₄[Fe(CN)₆]₃.xH₂O

• Yellow - (NH₄)₂MoO₄

• Violet colour - [Fe(CN)₅NOS]^4-

• Blood red colour - [Fe(SCN)]²⁺

147.

Among the following amines, which one has the highest pK, value in aqueous solution?

• Methanamine

• N, N-dimethylaniline

• Ethanamine

• Benzenamine

In the following equilibrium reaction,

2A $\rightleftharpoons$ B + C

the equilibrium concentration of A, B and C are 1 × 10^-3 M, 2 × 10^-3 M and 3 × 10^-3 M respectively at 300 K. The value of K_c for this equilibrium at the same temperature is

• $\frac{1}{6}$

• 6

• $\frac{1}{36}$

• 36

Which one of the following is the correct statement?

• HCO${}_3^{-}$ is the conjugate base of CO${}_3^{2-}$

• NH${}_2^{-}$ is the conjugate acid of NH₃

• H₂SO₄ is the conjugate acid of HSO${}_4^{-}$

• NH₃ is the conjugate base of NH${}_2^{-}$

Choose the weak monobasic acid, among the following

• H₃BO₃

• H₃PO₃

• H₃PO₄

• HNO₃